Induced flow well-point attachment



May 23, 1939. H, G. HOPKINS INDUCED FLOW WELL-POINT ATTACHMENT Filed Jan. 4, 1938 Patented May 23, 1939 UNITED STATES PATENT OFFICE 14' Claims.

My invention relates to an improvement in an assembly known in the art as a wellpoint of the self jetting type in which the wellpoint is sunk into the ground by jetting and is then used for pumping water or other liquids from the ground through screens assembled with the point. These types of wellpoints are more or less commonly used for unwatering soil, that is, removing the excess water from the soil in order to permit excavation or other constructional work to be carried on. In this unwatering of an area it has been thc usual practice to sink a number of wellpoints as a battery, connect to a manifold or a main suction pipe and employ a suitable pump which in creating a suction and hence partial vacuum outside cf the screen withdraws the surplus water from the soil.

usual type of this wellpoint the point is providedat the bottom with a jetting en d having a self closing valve which closes on the suction being developed through the wellpoint and hence to the ground surface. 'Ihe screens usualy surround a fluted pipe, such screens usually being formed of av screened cylinder and screen cloth or fabric on the inside. The course of the water is through the screens downwardly in the vertical iiutes inside of the screen, through perforations at the -bottom of the iluted pipe and thence upwardly through the center or inside of such pipe. However it as been found that this natural downward ow inside of the screens is insufficient to maintain these open. Therefore an object and feature of my invention both as to the apparatus and the method involves inducing a positive water ow inwardly through a section of the screen, this water following downwardly between the screen and the uted pipe and then mingling with the water drawn in by suction through the medium of a suction or similar pump. With my equipment and attachment a positive pressure is produced for instance in the upper part of the screen which by means of a water tight connection is shut off from direct flow to the surrounding ground area. If the remaining portion of the screen becomes clogged I may increase the pressure of the induced flow water to create a postive outward ow into the soil to free particles from the soil which clog the screens, however this outward ow is merely necessary as the increased volume of water by my induced flow maintains the screens sufficiently clean to carry (Cl. 16E-5) the water from the soil in unwatering and also a relatively large proportion of the fines or slimes.

A further characteristic and feature of my inventlon resides in using a collar which may be clamped to the upper end of the wellpoint and to the screen, this having a water tight gasket covering part of the screen. Connected to the collar is an induced ilow pipe preferably parallel to the suclion pipe of the wellpoint and by means of a plurality of perforations or ports, the induceddownward water ow is directed into the annular space between the upper part of the screen and the collar. The major length of the screen below the collar is still left for the eduction purpose of water from the well.

My invention is illustrated in connection with the accompanying drawing, in which:

Fig. l is a side elevation of a conventional wellpoint with my induced ilow attachment thereon, parts being broken away to illustrate interior construction.

Fig. 2 is a horizontal section on the line 2--2 of Fig. 1.

The conventional wellpoint is designated by the assembly numeral II. This employs the jetting point end I2 which has an outer wall I3 with a taper and open at the bottom I4. A transverse diaphragm I5 forms a valve seat having a valve opening IIS. A float ball I l which is usually made of wood or the like material, rubber covered, is retained in place by .a transverse retaining pin I8. A fiuted pipe 20 has its lower end 2| with a threaded connection to the wall of the point, there being a slight recess 22. The utes are connected by threads on the outer bends 23, thus leaving spaces for the downfiow of water into the chamber 24 above the diaphragm I5. The uted pipe has a series of water ow perforations 25 adjacent the bottom above the point of which one Arow having sufficient area is satisfactory. The i'luted pipe is covered by an assembly of screens 30. This is generally formed of an inner screen 3l formed of wire cloth or fabric and an outer foraminous shell 32. These are fitted at the bottom in the recess 22. The upper end of the uted pipe is connected to a coupling collar 35 by a welded connection indicated at 36, there being an upper recess 31 engaging the upper circular edge of the inner and outer screens. rI'rie Weld 35 or other means of attaching the fluted pipe forms an air tight connection so that there can be no leakage either up or down between the collar and the fiuted pipe. Lengths of coupled water flow pipe 38 extend upwardly to the ground level, the lowermost being screw threaded to the collar.

In the operation of the conventional wellpoint, these are sunk into the ground by jetting in whichcase Water is pumped down through the wellpoint, dlsplaces the ball I'I and discharges at the open end I4, thus forming a cavity permitting the ready sinking of the wellpoint with the assembly of pipes necessary to carry this to the desired depth. When it is desired to unwater, it is the usual practice to connect a series of the wellpoints to a manifold or other main pipe and operate by one suction pump.v This creates a suetion on the wellpoint. This suction coupled with the hydraulic head of the ground water causes the valve I1 to float upwardly against the seat diaphragm l5 and closing the opening or port I6. The water then flows inwardly through the screens, downwardly in the space 40 on the outside of the iluted pipe and inside of the screens, the water then entering the interior of the pipe at the perforations 25. It has been found that with this conventional type that the screens become clogged with sand, silt, and slimes carried by the ground water. For the most general use of this type of equipment is to unwater soil to render such soil in a more solid or firm condition for excavation or other building or like construction. Therefore most soils of this type have a considerable amount of fine material carried in through the screens and having a decided clogging action on the screens.

My invention therefore comprehends an induced ow attachment designated by the assembly numeral 50 which includes a split jacket 5|, the walls 52 of the jacket being substantially cylindrical -and provided with an overlap joint 53. This necessitates an offset section 54 and an outer lap section 55. The upper end of the jacket engages the coupling collar 35 which collar is preferably coated with a plastic mastic or other water resistant material so that there is no leakage after the attachment of a clamp 60. This clamp is merely a metal band with flanges 6l and a bolt 62 connecting the anges.

On account of the lower end ,of the jacket being spaced from the outer screen indicated as the foraminous shell 32, it is necessary to employ a packing gasket or ring 65. yThis is preferably made of rubber and is in the4 form of a ring. It is of sufiicient length to have a good contact with the foraminous shell and `is substantially the thickness of the collar 35; A lower clamping band 66 which is made the same as the clamp 6U then engages the lower :part of the jacket and on account of the jacket having the overlap joint, the gasket ring 65? may be compressed to form a water tight contact with the foraminous shell and alsowith thefwalls of the jacket. If desired the gasket may be sufficiently flexible to form a seal at the offset 54 of the jacket.

An induced flow head assembly 10 includes a tubular structure 1I closed at the bottom 12 and attached to the jacket. It is preferably formed integral with the jacket and through the connecting web 13 there are a plurality of ports 14 leading to the interior of the jacket. The flow head has a pipe section 15 extending upwardly above the web and preferably to about the location of the collar 35 where it employs a coupling 16 to which is connected a line of supply piple 11, the lowermost pipe only being illustrated. and this is preferably parallel to the line of pipes -38 and spaced a slight distance therefrom. It will be understood that the length `of screens on the wellpoint frequently run from a measurement of 32 to 40 inches between the pointed end I2 and the collar 35. Therefore my attachment jacket only covers a small portion of the screen, leaving the major portion open below the gasket'ring 65 which projects slightly below the end of the jacket.

The manner of operation and functioning of my invention is substantially as follows: The assembly may be jetted in position in the same manner as the conventional wellpoint but of course if desired additional water may be pumped downwardly through the pipes 11. Where the ground area to be unwatered is of sufficient size necessitating a bank or a considerable number of wellpoints, the pipes 11 may be connected to a supply manifold or connection or each connected by an ordinary hose. While the water is being pumped from each wellpoint or the assembly in the ordinary manner, water is forced down under pressure through the pipes 11, developing the desired flow. This causes an inward flow of water through the screens at the section covered by the jacket. This water ows downwardly in the space 40 on the outside of the uted pipe where it meets the water and silt drawn in through the lower part of the screens. The action of theclear water in flowing longitudinally of the Screens and in a downward direction loosensA any silt or fines carrying these with the ow of water to enter the inside of the fluted pipe through the openings or ports a't the bottom and thence being mixed with the upward iiow of water drawn in through the screens from the soil. Should the wellpoint become quite clogged so that 'it is ineicient, the pressure and the amount of water pumped through the pipe 11 may be increased and thus direct a positive outflow through the uncovered portion of the screens. This therefore dislodges any clogging' matter settling on the outside of the screens. Therefore the screens being cleaned permit the proper functioning of the wellpoint in the usual manner of pumping.

An important feature of my invention in using the induced flow of water which is pumped under a positive pressure is that it allows the use-of much coarser screens in the wellpoint than would otherwise be practical without the induced ow attachment, hence by using the coarse screens together with the induced flow, more material from the soil is allowed to enter the wellpoint. This by ordinary pumping might be too thick for -proper flow but when mixed with the clear induced ow water. ythe dilution provides a fluid which may be readily pumped and carry the soil particles to the surface, therefore after a period of time the nes are washed out of the soil surrounding the bottom or the wellpoint and leave -the coarse sands and gravel surrounding the screens which form an ideal surrounding material for pumping. When this condition is reached the induced ow water may be shut off and the wellpoint pumped inthe ordinary manner.

Various changes may be made in the details of the construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. In a device as described, the combination of a wellpoint having an intake screen and a pipe for conducting water flowing inwardly through the screen to the top of the well combined with an induced flow attachment including a jacket surr rounding part of the screen with means to ow water from the top of the well into the jacket and thence through the portion of the screen covered by the jacket.

2; In a device as described, the combination of a water pumping assembly including a pipe for upflow of water by suction, a screen, a connection between the screen and the pipe whereby water owing inwardly through the screen flows upwardly in the pipe by suction, an induced ow attachment including a jacket surrounding part of the screen, there being a space between the jacket and the screen and means to ow water from the ground surface downwardly to the jacket whereby such water flows inwardly through the screen and upwardly through the suction pipe.

3. In a device as described having a wellpoint with a screen for inflow of water from the soil and an upflow pipe for the screened water combined with an induced fiow device including a structure surrounding part of the screen with means to ow water from the outside of the screen inwardly, the means to iiow the water inwardly through the screen including a pipe connection leading tc the top of the well with a downward iiowof water and means forming a space around the screen for the circulation of the induced ow water to circulate around the outside of the screen.

4. In a device as described in which a wellpoint is provided with an upflow pipe for water with an inlet adjacent the bottom, a screen surrounding the pipe with provision for a down ow of water inside the screen and upwardly through the pipe combined with an induced flow attachment including a jacket structure surrounding part of the screen and having means to supply water from the surface of the ground to the jacket, whereby the water entering the screen inside of the jacket may flow longitudinally thereof between the uncovered portion of the screen and the said pipe.

5. In a device as described in which a wellpoint is provided with a iiuted suction pipe with a connection to the top of the well, a screen surrounding said pipe for inow of water and flow ports adjacent the lower end of the iiuted pipe combined with an induced flow attachment including a jacket surrounding at least part of the screen, there being an annular space between the screen and the jacket and means to ow water from the ground level to the jacket whereby this induced flow water flows inwardly through the portion of the screen covered by the jacket and then iiows longitudinally of the iluted pipe to the intake ports, the jacket having a substantially water tight connection at the portion of the screen covered by the jacket to force all the induced flow of water through the screen at the jacket.

6. In a device as described and claimed in claim 5, the means'to flow water to the jacket including a tubular structure connected to the jacket with ports leading to the annular space between the jacket and the portion of the screen covered thereby and a pipe connection from said tubular structure to the top of the well.

'7. In a device as described having a wellpoint with a screened portion for iniiow of water from soil and an upiiow pipe for the screened water combined with an induced flow device including a jacket surrounding part oi' the screen, means forming a water tight seal at the upper and the lower portion of the jacket, an induced ow head assembly secured to the jacket and connected to the interior thereof by a plurality of ports, there being an annular space between the inside of the jacket and the screen and means to flow water from the top of the well to the ow head assembly.

8. In a device as described and claimed in claim 7, the jacket having a longitudinal joint and clamps securing the upper and lower portions of the jacket to the wellpoint and being adapted to devefop a substantially leak-proof joint.

9. In a device as described having a wellpoint with a coupling collar adjacent the top and a screen extending below the collar combined with an induced flow assembly including a jacket surrounding the collar and an upper portion of the screen, means forming a water tight joint between the collar and the screen, an induced ow head assembly connected to the jacket, there being a plurality of ports leading from the said head to the inside of the jacket and there being an annular space between the jacket and the screen and means to flow water from the ground surface to the head ow assembly.

10. In a device as described and claimed in claim 9, the said jacket having a longitudinal joint from top to bottom, the water tight connection to the screen including a compressible gasket ring engaging a portion of the screen and the inside of the jacket adjacent its lower end together with a clamp surrounding the jacket and substantially in horizontal alignment with the gasket.

11. In a device as described and claimed in claim 9, the jacket having a longitudinal joint from top to bottom, a means forming the said water tight joint including a mastic composition between the collar and the upper part of the jacket and a compressible gasket ring between the lower part of the jacket and the screen, together with clamps attaching the jacket to the collar and. surrounding the jacket in substantial horizontal alignment with the gasket.

with an upow pipe, a screen surrounding said pipe, there being a space between the screen and the pipe, the pipe having an inflow means adjacent the lower end of the screen for the inflow of Water passing inwardly through the screen and downwardly in the said space combined with an induced ow device having a water conning means surrounding the upper part of the screen with a water connection to the ground surface for an induced ow of water through the upper part of the screen, the said induced flow water being adapted to owidownwardly in the said space and to mix with the water iiowing inwardly through the screen from the soil.

13. In the art described in which water is pumped from soil by means of a wellpoint in which the water from the soil ows inwardly through a screen, the major portion of the water ows downwardly inside of the screen and outside of a ow pipe, thence enters the flow pipe at the bottom and flows upwardly in the flow pipe by a pumping action which comprises inducing a iiow of water separate and distinct from the water of the soil and the water pumped upwardly, confining the owingwater of said induced ow around part of the screen to enter such screen and to flow downwardly mixing with the water owing inwardly from the soil through the screen and also the iiow'ywater cleansing the screen.

14. In the art described and claimed in claim 13, increasing the pressure of the flow water to positively force some of the ow water outwardly through the portion of the screen through which the soil water normally enters. f

' HERBERT G. HOPmINS. 

